fast_obj VS assimp

The operations you're talking about with the example of loading 3d data is the realm of parsing, and there's a LOT of theory available and a LOT of code available for how to implement things -- there are TONS of options. Since you don't know where to start you should investigate parsing generally in C. I highly recommend you take a look at an existing library in C that loads 3d data, like this library https://github.com/thisistherk/fast_obj/blob/master/fast_obj.h that deals with OBJ the format.

I've replaced tinyobjloader with fast_obj which speeds up model loading process significantly. Here is a good article comparing different obj loaders.

I wanted to say try writing your own like I did, then I remember I made it in c++ with string & stringstream std lib :(. I don't know how much would it take you to write it yourself, might try it myself. After a quick search I think this one has a pure c version: https://github.com/thisistherk/fast_obj

Oh I see. I was talking about writing a program in the language of your choice that does this, it's not very difficult. If you use C or C++ you can load the file with https://github.com/thisistherk/fast_obj to make it even easier.

If you use something like libassimp https://github.com/assimp/assimp it will allow you to import these and access the data to generate your Vertex Array Objects then render to a frame buffer object.

If you just want to load other data in a relatively simple fashion, assimp https://www.assimp.org supports loading a bunch of different formats and is pretty easy to use.

The emscripten interface for the assimp library. It runs entirely in the browser, and allows you to import 40+ 3D file formats and access the result in JSON or glTF format. This is not a full port of assimp, but an easy to use interface to access it's functionality.

I ran into what sounds like a similar problem a few months ago. It turns out this was an assimp bug: https://github.com/assimp/assimp/issues/1974

You could give assimp a go (there is a python version) i've used it for 3DS before then you can export to something else. https://github.com/assimp/assimp/blob/master/port/PyAssimp/README.md

I have checked the source code for GLTF for this and it is not handled by Assimp. I created an issue as in their Github.

Assimp is your friend

Have you read the license? It's quite permissive. https://github.com/assimp/assimp/blob/master/LICENSE

There is probably some library more specific to your use case, but you can use assimp to load 3d models in C++.